Fastening device for flexible printing plates



Aug. '7, 1923.

s. C. FORRESTER FASTENING DEVICE FOR FLEXIBLE PRINTING PLATES Filed June14. 1921 Patented 7, W233,

SAMUEL C. FORRESTER, F ATLANTA, GEURGIA, ASSIGNOR T0 FUL'JIUN BAG aCU'E'EUN MILLS, 9F ATLANTA, GEQBQEA.

FASTENING DEVICE 1 03B FLEXIBLE PRINTING JELATEQ.

Application filed June 14, W21.

To all whom it may concern."

Be it known that ll, SAMUEL Cnrrronn Fonnnsrnn, a citizen of the UnitedStates, residing at Atlanta, in the county of Fulton e and State ofGeorgia, have invented new and useful Improvements in Fastening Devicesfor Flexible Printin Plates, of which the following is a speci cation.

This invention relates to the art of printit) ing, but more particularlyto a simple, eflective and expeditious means for operatively positioninga flexible printing element upon a printing cylinder.

()ne of the principal objects of this invenw tion is to effect a simplefastening device for securing a flexible printing element to the surfaceof a printing cylinder, in manner to facilitate its rapid attachment ordetachment when occasion requires.

Another important object of this invention is to prov'ide a fasteningdevice of the character specified, which will enable a fiex1- bleprinting element to be stretched taut over the printing cylinder and atthe same time affords an absolutely uniform distribution.

of the tension.

Other objects of this invention are: to

. provide a fastening means which is simple,

inexpensive, durable, and eflective 1n operation; likewise one whichwill eliminate much of the annoyance and loss of time experienced withthe fastening means now employed for this purpose.

With these and other objects in View, which will become apparent as thedescription proceeds, the invention resides in the construction,combination and arrangement of parts, hereinafter more fully describedand claimed, and illustrated inithe accom panying drawings, in whichlike characters of reference indicate like parts throughout the severalfigures, of which:

Fig. 1, is a plan vie-w of a printing cyl1n der equipped with a flexibleprintingelement secured in accordance with the principle of thisinvention;

Fig. 2, is a fragmentary transverse section, with parts in elevation;and

Fig. 3, is a detail plan of one of the clastic connections.

Briefly stated, this invention comprises a printing cylinder having tworows of ciraerial lt'o. $77,,t10.

cumferentially spaced anchoring members, between which a flexibleprinting element is stretched, one longitudinal edge of the elementbeing in engagement with the gripper line or-upper roW of anchoringmembers, the other being connected to the lower or back row through theinstrumentality of elastic bands or straps.

It has been the prevailing practice to secure flexible printingelements, such as that described in pending application, Serial Number453,759, filed March 19, 1921, method and apparatus for producing aresilient printing plate, with cord or wire fastening means securedaround the cylinder, but with the use of these much time, labor, andmaterial is lost, due to adjustment of the plate and defective printingresulting from buckling of the printing element caused by an unequaldistribution of tension. It is, therefore, the aim and purpose of thisinvention to eliminate these difliculties by providing a fastening meanswhich will enable the plate or printing element to be quickly mounted onthe cylinder in a manner to preclude its creeping or buckling, the causeof defective printing.

lln the illustrated embodiment characterizing this invention, there isshown a cylinder 1 of a rotary printing press, having its surface formedwith an annular series of mortises 2 which are arranged incircumferentially spaced relation around the cylinder, with which theyare coextensive.

These mortises or channels 2 accommodate in end to end relation a seriesof tenons in the nature of short blocks 3, which lie with their uppersurfaces coincident with that of the cylinder. One row of blocks 3 isprovided with a series of permanently mounted aligning studs 5,constituting what may be termed a gripper line; while the remainingblocks are formed with suitable threaded openings to receive screws 5,which forms the complement of the gripper line. These screws 5 may betransferred from one row of blocks 3 to another as occasion might require, depending on the width of the flexible printing element which isstretched between them.

To enable operative positionment of the flexible printing element 6 uponthe printing cylinder, said element is provided along its longitudinaledges with a plurality of grommets or eyelets 7. The grommets along oneedge of the printing element being adapted to embrace studs 5, whilethose in the other are adapted to engage hooks 8 secured to the upperends of elastic bands 9, the free ends of which are provided with rings10 for engagement with screws 5'.

From the preceding structural outline it is manifest that with the useof this fastening means, the flexible printing element may be readilymounted in proper printing position by simply arranging the lower orback row of screws 5 in proper spaced relation with respect to the studs5 in the gripper line, dependent on the width of the print-- ingelement, engaging the grommets on one edge of the flexible printingelement with studs 5 of the gripper line, and stretching the elasticbands 9 until they are of sufiicient length to enable rin s 10 to engagethe complemental screws 5. As the elastic bands are stretched,necessarily the flexible printing element will be drawn taut over thesur face of the printing cylinder with the tension applied uniformly toall parts thereof.

In conclusion, it will be seen that straps 9, owin to their elasticity,effect a uniform distribution of the tension, thus precluding thepossibility of defective printing resulting from cree ing or buckling ofthe printing element. Ioreover, the permanent line of studs 5 with whichone edge of the printing element may be engaged, enables the saidelement to be instantly snapped into place and eliminates the loss oftime incurred in the removal of the several screws heretofore employedincidental to mounting the rinting element on the cylinder.

Athough in the foregoing, certain ele ments ma have been set forth asbest adapted to per orm the functions allotted to them, nevertheless, itis to be understood that various minor changes as to form, substance,etc., may be resorted to within the scope of the appended claims withoutdeparting from or sacrificing any of the principles of this invention.

Having thus described my invention, and without enumerating variationsand equivalents, what I desire protected by Letters Patent is as setforth in the following claims:

1. A flexible-plate mounting for cylinder presses comprising a cylinderhaving an annular series of mortises arranged in circumferentiallyspaced relation around the cylinder, and anchoring means associated withthe said cylinder, said means including filler blocks engaged in thesaid mortises, and an choring studs having threaded engagement with thesaid blocks and arranged in two circumferentially spaced rows.

2. A flexible-plate mounting for cylinder presses, comprising acylinder, and plateanchoring means arranged on the cylinder in twocircumferentially spaced lines, one of said lines being adjustablecircumferentially of the cylinder and including a variable number ofplate-attaching units.

3. A flexible-plate mounting for cylinder presses comprising a cylinderhaving circumferentially spaced parallel sets of plateanchoring membersbetween which a printing plate is adapted to be secured, said sets ofanchoring members being relatively adjustable circumferentially of thecylinder to accommodate plates of varying widths, and elasticplate-tensioning means for securing the plate to the anchoring membersof one set.

4. In a flexible-plate mounting for cylinder presses, the combinationwith a printing cylinder having two circumferentially spaced lines ofplate-anchoring members, one line of which has adjustmentcircumferentially of the cylinder, of a plurality of plate-tensioningelements detachably connected at one end to the said adjustable members,and a flexible printed plate having one edge detachably connected withthe opposite ends of the tensionable elements,

tively stationary and adjustable sets of plate-anchoring members betweenwhich a printing plate is securable, the members of the said adjustableset having adjustment bot-h longitudinally and circ-umferentially of thecylinder.

6. A flexible printing-plate mounting for cylinder presses comprisingthe combination with a printing cylinder having an annular series ofmortises arranged in circumferentially spaced relation around thecylinder, of filler means removable contained within the said mortises,a permanent row of plate-anchoring members carried by the filler meansof one mortise, and an adjustable row of plate-anchoring members engagedwith the filler means of another mortise, the members of the saidadjustable row being transferable from the filler means of one mortiseto another.

7. A flexible printing-plate mounting for cylinder presses comprisingits combination with a printing cylinder having an annular series ofmortises arranged in circumferentially spaced relation around thecylinder, of a row of short blocks in each mortise, aligning studsmounted on the blocks of one. mortise and constituting the permanentgripper or starting line of the cylinder, a plurality of screwsthreadedly engageable with the blocks of the other rows or mortises toform the complement of the gripper line and being transferable from onerow of ees-pee blocks to mother, s flexible printing-piste bands beingprovided with a hook eh one end disposed between the said lines of studsand engaged in e grommet of the plate and e screws and having grommetsalong opposite ring at the other end engaged over one of m edges, thegrommets of one edge being enthe said screws.

5 geged over the said studs, and e series of S. C. FURRESTER.

elastic bends between the opposite edge of Witness: the plate and thesaid screws, each of said T. W. THORNTON.

